Fuel Quantity for Blue Water Cruising

[Talbot]

On my Catamaran, I have 2 x 3YM30 engines and a diesel generator. I have a total of 360 litres (95 Gallons US) in fuel tanks. I know a lot of people cruise with lots of additional diesel in jerrry cans.

What do you consider to be an adequate supply when going across the pacific?

[StuM]

Do you have plenty of solar/wind to keep your batteries charged or are you relying on the engines/generator to charge them?

[TeddyDiver]

Do the math. Consumption of power, recharge need with power, amount of motoring etc. Nobody can tell but you.
For me, some 1.5 tons of fuel for a month of arctic cruising..

[MarkJ]

We used 38 gallons to cross the Pacific and that was without solar panels!

That was Panama to Sydney

[svseachange]

Originally Posted by StuM

Do you have plenty of solar/wind to keep your batteries charged or are you relying on the engines/generator to charge them?

That is a really good question. The only way to know the answer to this question is to spend a lot of time unplugged and underway. You will not understand your energy needs until to you do this.

For example, it took almost six months for us to understand our energy needs at anchor. We did a lot of one to two day sails into the wind as we beat south east along the US Atlantic coast. By the time we turned west we felt our solar met our needs.

We are now doing longer sails in tradewinds with big following seas and are finding our autopilot draws a lot of juice in these conditions and our solar does no longer meets our needs. This means we have to hand steer more or use diesel to charge batteries.

I am sitting in Panama contemplating a Pacific crossing thinking about the same question. We need more solar, more hand steering and/or more diesel.

[RockWoods]

Never heard anyone say they had too much fuel for a crossing.

[MarkJ]

Originally Posted by RockWoods

Never heard anyone say they had too much fuel for a crossing.

We had too much fuel. We refuelled in Tonga for safety and the duty free price was $2.65 US per LITRE, thats over $10 per gallon!

And we didnt need none of it

[Talbot]

Originally Posted by StuM

Do you have plenty of solar/wind to keep your batteries charged or are you relying on the engines/generator to charge them?

Sorry that I am so slow to rspond, but I am at work, and supposed to be working!

I have 555 watts of solar.
I have a very small wind enerator that in reality only keeps the generator battery at full charge.

[Talbot]

Originally Posted by svseachange

That is a really good question. The only way to know the answer to this question is to spend a lot of time unplugged and underway. You will not understand your energy needs until to you do this.

For example, it took almost six months for us to understand our energy needs at anchor. We did a lot of one to two day sails into the wind as we beat south east along the US Atlantic coast. By the time we turned west we felt our solar met our needs.

We are now doing longer sails in tradewinds with big following seas and are finding our autopilot draws a lot of juice in these conditions and our solar does no longer meets our needs. This means we have to hand steer more or use diesel to charge batteries..

All very good points, I have converted to LED totally. My autopilot is a modern gyro rate assistance version which should use a lot less power than the older style, and the boat is a catamaran, which is MUCH easier to steer downwind in the trades. All of which should mean that there is more power available than needed. I have a watermaker which should run adequately directly from the solar, so that is another non-use of the generator. But I am attempting to second guess myself here, and use others expertise. I do plan to spend a year in the mediterranean before moving to the west.

[donradcliffe]

95 gallons should be enough for you, but you will want to take 4 jerry jugs with you because there are no fuel docks. The jerry jugs take up as much room empty as they do full.

[Roy M]

In 1989, YANMAR ENDEAVOR crossed the Pacific from San Francisco to Honolulu, a forty-foot high tech trimaran with no sails, powered by twin 25-HP Yanmar diesel outboards. We used just under 400 gallons of fuel, much of it carried in fuel bags. Our speed averaged about 11 knots. That should provide a high-end fuel quantity limit for the discussion.

[Aussiesuede]

Figure 50 hours of motoring as your high ceiling between N/S America and the Marquesas and work backwards from there. ie. @1.5gph that equates to 75 gallons of fuel. Worse case is a refuel in The Marquesas @ about $1/ liter with a fuel duty exemption form organised by your agent. But with adequate wind/solar to meet your dailys, 95 gallons should be more than sufficient for your entire crossing.

If you're making the typical first landfall in the Marquesas, don't make the typical 1st timer mistake of landing in Nuka Hiva. That leaves you beating against wind and current to get to the other lslands. The current accellerates when it hits the Islands so approach from well to the east and you'll eliminate need to motor. Hiva-Oa, then down to Tahuata, and Fatu-Hiva, then up to Ua-Pou, and finally Nuku-Hiva.

Another tip is to organise your agent prior to arrival. Polynesia yacht Service is awesome and eliminates the need to post a $1100 bond, which if you put on credit card, the bank fees end up being about the same as the agent fees anyway, but without the benefit of bond & fuel duty exemption.

[markpierce]

You're a sailor. You shouldn't need much fuel. That is, unless you plan to cruise in windless seas or choose to head directly into prevailing winds.

[JazzyO]

Originally Posted by TeddyDiver

Do the math. Consumption of power, recharge need with power, amount of motoring etc. Nobody can tell but you.
For me, some 1.5 tons of fuel for a month of arctic cruising..

Doing the math, if you use all of it, you use 6.4 gallons per day. I cannot imagine using that much on a sailing vessel. But you must have good reason to take that much (I presume a large part of it is backup considering the region you sail in? Even so - it seems a lot.).


Onno

[gjordan]

If your solar panels are marginal, you might have to run the genset every 2 or 3 days for an hour. That (I am guessing) might be a half gallon every third day. 30 day passage=5 gallons if every third day ,or 7.5 gallons if every other day. The rest of your fuel is just for harbor entrances and if you go nuts below 4 knots. It is a sailing trip, learn to relax. Jugs are needed, since you will sometimes be rowing fuel out jug at a time. Remember ,it is a sailboat. Have a great trip. _____Grant.